This invention relates to an information processing apparatus and an optical head incorporated therein. More particularly, the present invention relates to an information processing apparatus of high portability which has a reduced thickness and size and a small-sized, weight-reduced optical head for use in the apparatus.
When an optical disk is used as a memory of a portable information processing apparatus, such as a lap-top computer and the like, it is desirable for the optical disk to be provided with a protective case and to be reduced in thickness. In the conventional optical disk, the surface deflection of the disk was allowed to be about 1 mm, and the distance between disk substrate and objective lens surfaces, called the work distance, was set to be about 2 mm. Since the disk substrate had a thickness of 1.2 mm and this thickness was added to the thickness of the lens, the focal distance of the lens was required to be 4.0 mm or more, and the extent to which the thickness of the information processing apparatus could be reduced was limited.
On the other hand, on IC card, floppy disc or an optical card have been conventionally used as a memory of the portable information processing apparatus represented by a lap-top computer. However, concomitantly with an increase in throughput of the information processing apparatus, a need for handling large amounts of information, such as image data, has occurred. Under the circumstances, the conventional IC memory, floppy disk and optical card suffer from shortage of storage capacity, and so the near for a small-sized and large-capacity memory has arisen.